Safety starting mechanism.



C. McCLAIR.

SAFETY STARTING MECHANISM. APPLICATION FILED mm. 1906.

Patented Apr. 13, T915.

2 SHEETS-SHEET 1.

C. MCCLAIR.

SAFETY STARTING MECHANISM. APPLICATION FILED JAN. 6. I906.

2 SHEETS-BHEET 2.

Witnesses.

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,. engine shaft to which onanrns meters, or scnnnncranr, new roan.

SAFETY STARTING IltiECHfitlil'TSild.

specification of Letters Patent.

Patented Apr. 11.8, 18115.

Application filed January 6, 1908. serial No. 23%,889.

To all whom it may concern Be it known that ii, Cannes MCCLAIR. a citizen of the llnited States, residing at Schenectady, county 01 Schenectady. and State ot New York, have invented a new and useful improvement in Safety Starting Mechanism, or which the following is a specification.

My invention relates to starting means for devices which must be started by some external or auxiliary source of ower and which n1ay start in the wrong direction.

lit relates more particularly to starting deices for internal combustion enginesnvhich,

are usually started by hand, and which may back tire and start to run in the wrong direction, thereby damaging the starting device and often inflicting serious injuries on the operator who has hold of the starting crank or similar starting member.

The. object of my invention is to provide an improved safety starting means by which an internal combustion engine or similar device can be started without danger of injury or damage in case the engine back fires and starts in the wrong direction.

Another object is to provide a safety in g means which cannot be moved backward try the engine but which can be easily moved backward at will by the operator so that if desired the starting crank or member can he moved backward at any time to tacilitate the starting operation, as, for example, where it is desired to permit the crank shaft to oscillate once or twice during starting; and a further object is to provide a starting device which is in general an improvement on the starting devices heretofore commonly used.

My invention will best be understood by reference to the accompanying drawings, which show merely for purposes of illustration some of the'various forms in which my invention may be embodied and in which Figure 1, is a sectional view of an improved torm of starting device especially adapted to an explosion engine; 1 ig. 2, is an endview of the starting device with the starting crank in operative position; Fig. 3, is a view in perspective of the end of the the starting crank is applied; Fig. 4 is a view of the starting crank. 1 ig. 5 is a sectional view. and Figs. ti and 7 are end views of a modification of the form of device-shown in Fig. 1.

-which the pawls 195 engage.

start-- An improved starting device for engines of this type is shown in Fig. 1. The shatt 13 is hollowed out, and in the space so formed is placed a rod 186. This rod is provided with a pin 187 which passes transversely through the rod 186. Therod 186 is threaded and carries nuts 188 and 189., which nuts engage a spring 190, which bears against the shoulder 191 formed in the shaft 18. The pin 187 extends through a spiral slot 192 in the shaft 13. A bracket 193 is secured to the frame work of the engine and carries a ring 19-1. (in this ring are mounted pawls 195. A starting crank 196 is provided which has a safety device to prevent reverse rotation of the crank by the engine shaft. The particular form of crank illustrated carries a ratchet wheel 197, with The starting crank is best shown in Fig. 4, and comprises of a hub having a hollow therein which-titsover the end ot the shatt 13. The hub or" the crank is provided with notches 198., which engage the pin 187. Tn using this starting crank it is placed on the end ot the shaft 13, so that the notches 198 engage the pin 187. its the crank is turned in the direction of the arrow the pin 187 has a tendency to travel along the slot 192. llt is resisted in this tendency by the spring 190 which is of sufficient strength to prevent the pin traveling along the slot 192., upon the application of a mans strength to the starting crank 198. lln case the engine back fires, however. the crank 196 begins to turn in the direction opposite the arrow in Fig. 41. The pawls 195 engage the ratchet 191. and lock the starting crank 196. As the shaft 13 continues to turn backward the force exerted on the pin 187 is sufficient to cause said pin to travel in the slot 192 compressing the spring 190. Eventually the pm 181' travels along the slot 192 such a distance that it goes out of the recess 198. When this occurs the "pin 187 moves along the surface 199 of the starting crank and as there is no longer anything to press the spring 191), said spring expands and through the pin 181' throws the starting crankto the right and out of engagement with the pm 187, thereby protecting the operator trom injury.

lFig. 5 shows a form of this device 1n which the spring is mounted on the starting crank, and the shaft 13 is solid. A casing 216 carries a sleeve 217, which tits over the the lug 219. Th

. which is attached end or the shaft 13, and is provided with recesses which engage the pm in the end of the shaft. This sleeve slides on a'centra-l boss in the casing, and is held in position by the bolt 218, which passes through a spiral slot in the sleeve. position shown by a spring 227, which is strong enough to resist the strain of starting the engine. The casing 216 carries lugs 219 and 228, and a pawl 220 is pivoted to is pawl has attached thereto of a spring 221, the other end of a lug 222, carried by a crank 223, loosely mounted on a projection 22a of the casing 216. The crank is held in placeon the pro ection by a nut 225. A in 226 is attached to the crank in such positlon as to engage thepawl on-the o osite side to that engaged by the spring. he lug 222 projects-between the lugs 219 and 228, and is of less width than the space between the lugs, so that the crank 223 can be moved a short distance without the lug 222 engaging either of the lugs on the casing. The pawl 220 engages a ring 229 which is mounted on the engine frame similar to the ring 194 shown in Fig. 1. The inner side of this ring is formed in a series of steps as shown, with which the end of the pawl engages. hese steps are so formed that as the crank turns in the starting direction, as shown by thearrows in Fig. 4 and Fig. 6, the pawl one end slips oyer the steps, but when the sleeve 216 turns in the opposite direction, the pawl engages with one of the steps and'the reverse rotation of the sleeve is prevented. The surface of the steps with which the end of the pawl engages is formed as the arc of a circle of which the pivot of the pawlv is t e center and the length of the pawl is the As -a consequence of this f surface, pressure of the pin 226 against the pawl willresult in a movement of the pawl toward the shaft, the end of the pawl sliding along the surface of the step. I

' be started, the de- When' the eliglne is to vice shown in ig. 5 is applied to the end of 223, owing to the eng ment of the bolt 218 with the spiral slot in the sleeve. T is movement is resisted by the spring 227. If the engine backfires, the device tends to turn in the awl engages the ring 229, and stops it. s the shaft 13 continues to turn backward, the spring yields, and the device is released from the shaft. In starting an engine, it is often desirable to turn the starting crank backward at will while the crank shaft is stationary, or to permit the crank shaft to turn in the reverse direction, or to oscillate the crank shaft a few The sleeve is held in the safety times to draw in a charge. This may be done with this device, since when the crank is moved backward in the direction of the aTFow shown in Fig. 7, the crank and sleeve 216move relatively to each other and change from the starting relation shown in Fig. 6 to the reversing relation shown in Fig. 7 the pin 226 depresses the pawl 220, out of engagement with the ring 229, and the safety device is thereby rendered inoperative, so that as long as the reversing relation of the crank and sleeve is maintained the starting device, or the shaft to which the starting device is applied, can be turned backward as freely as though the safety pawl 220 were starting device from the shaft. The protection'against injury due to back firing is never lost, since as soon as the engine shaft turns faster in the reverse direction than the starting crank the sleeve 216 moves relatively to the crank until their relative position becomes the starting position shown in Fig. 6, whereupon the arrow in Fig. 5 the pawl is in engagement.

at I claim and desire to secure by Letters Patent is:

1. In an internal combustion engine, the combination with a starting crank having a handle, of a safety device for preventing re verse movement of said crank by the engine, and means for rendering said safety device inoperative when pressure is exerted to turn the handle in the reverse direction.

starting device comprising a sleeve for engaging the device to be started, an operating member for rotating the sleeve, a device normallv operative to prevent device inoperative when pressure is exerted to turn the handle 1n the reverse direction.

and an actuating handle movable relatively to the sleeve, of a safety device normally operative to prevent reverse movement of normal strain in staiting, but yields and permits the pin to travel along the slot when the strain is abnormal.

. 5. starting device for internal combustion engines comprising a sleeve carrying i 17. A safety cranking device comprising .aclutch member capable of being connected to the crank shaft of an engine, a coiiperating clutch member adapted to interlock with the first clutch'member, a crank for operating said clutch members in a direction for starting. the engine, a ratchet andsafety device for holding said idle clutch member from reverse rotation, and means actuated by reverse rotation of'said crank for holding said awl out of engagement with said ratchet dining reverse rotation of sai crank.

. 18. A starting mechanism comprising a starting member capable of being rendered operative or inoperative at will, means for establishing between said starting member and the device tobe started a connection constructed to remain rigid-under normal starting strain but to yield under abnormal strain, and means actuated in response to the yiel of said connection to' a'utomatically render said starting member inoperative during reverse-rotation of the device to be started.

19. A starting mechanism comprising a rotatable startingmember movable longitudinally into inoperative position, and a normally rigid torque transmitting resilient connection between said starting member pawl messes I and the member to be started constructed to permit relative movement of said members in response to abnormal strain and to move said starting member longitudinally into inoperative position in response to relative movement of said members. i

20. A starting mechanism com a cooperating rotatable member engaged thereby and movable longitudinally out of operative relation thereto in response to abnormal thrust exerted by said starting member, and a spring for normally holding said coo eratin memher in a position to be engaged by s'ui starting member and for permitting said cooperating member to move under abnormal pressureexerted by said starting member out o engagement with said starting member into position to thrust to move said starting member longitudinally into its inoperative position.

testimony whereof, I have affixed my in the, presence of two witnesses.

signature CHARLES MCCLAIR.

Witnesses:

BENJAMIN Team FRANK O. QBmnn.

exert a longitudinal- 

